The NPSI Knowledge Harvest brings together information from across the National Program for Sustainable Irrigation (NPSI) projects, highlighting key findings and promoting wider understanding. Key themes within the Harvest are: 1. Irrigation Overview - facts, figures and key concepts about irrigation. 2. Water Delivery Systems - the efficient storage and distribution of water for irrigation. 3. On-farm Irrigation Essentials - principles for efficient irrigation.4. Recycled Water - recycling treated effluent and stormwater for irrigation.